Flame resistant organic textile through treatment with halogen containing soluble methylol phosphine adducts

ABSTRACT

Process for producing flame-resisting textiles comprising impregnating the textile with a solution contaiing an acid producing catalyst, an amine or amide nitrogenous compound and an adduct prepared by reacting tris (hydroxymethyl) phosphine with halogen substituted phenols which contain one or more hydrogens ortho or para to the phenolic hydmoxyl group, and heating the impregnated textile to a temperature from about 90* to 170*C. until the adduct and nitrogenous compound react to produce an insoluble product.

United States Patent Daigle et a1.

- [45 1 Feb. 25, 1975 FLAME RESISTANT ORGANIC TEXTILE THROUGH TREATMENT WITH HALOGEN CONTAINING SOLUBLE METHYLOL PHOSPHINE ADDUCTS lnventors: Donald J. Daigle, New Orleans;

Wilson A. Reeves; George L. Drake, Jr, both of Metairie, all of La.

Assignee: The United States of America as represented by the Secretary of Agriculture, Washington, DC.

Filed: Dec. 15, 1972 Appl. No.: 315,738

Related U.S. Application Data Division of Ser. No. 141,447, May 7, 1971, Pat; No. 3,746,191.

U.S. Cl 117/136, 117/62.2, 117/137, 117/138.8 F, 117/138.8 N, 117/138.8 UA, 117/141,117/143 R Int. Cl C09d 5/18 Field of Search. 117/136,141, 143 R, 138.8 F, ll7/138.8 N, 138.8 UA, 143 A, 137, 62.2; 260/6065 P [56] References Cited UNITED STATES PATENTS 3,619,113 11/1971 Stockelet a1. 117/136X 3,698,854 10/1972 Donaldson et a1 117/137 X Primary Examiner-William D. Martin Assistant Examiner-Theodore G. Davis Attorney, Agent, or FirmM. Howard Silverstein; Max D. Hensley [57] ABSTRACT 3 Claims, N0 Drawings 1 FLAME RESISTANT ORGANIC TEXTILE THROUGH TREATMENT WITH HALOGEN CONTAINING SOLUBLE METHYLOL PHOSPHINE ADDUCTS This is a division of application Ser. No. 141,447 filed May 7, 1971 now US. Pat. No. 3,745,191.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to new halogen and phosphorus containing compounds; to halogen, phosphorus, and nitrogen containing polymers; and to processes for their use in the production of flame-resistant organic fibrous material. More specifically, it deals with a method of producing halogen containing soluble methylol phosphine adducts and the use of these to produce insoluble polymers and flame-resistant organic fibrous products through reaction of the adduct with nitrogenous compounds.

As employed throughout the specifications and claims of this invention, the term THP refers to the compound tris(hydroxymethyl)phosphine. The term halogen containing methylol phosphine adduct refers to soluble compounds produced by reacting THP with certain halogen containing phenolic compounds.

Copending application Ser. No. 141,356by Daigle, Reeves, and Drake filed May 7, 1971 relates to the production and use of polymers made by reacting THP with hydroxy benzenes of the group consisting of phenol halo hydroxyl, and alkyl substituted phenols in which hydrogen atoms are attached to at least two ring carbon atoms which are ortho or para to a hydroxyl group.

Copending application Ser. No. 141,446 by Donaldson, Daigle, Reeves. Drake and Beninate, filed May 7, 1971, and now US. Pat. No. 3,734,684, filed relates to soluble methylol phosphine adducts prepared by react ing THP with a monomeric nitrogenous compound which contains at least one member of the group consisting of hydrogen atoms and methylol radicals at tached to trivalent nitrogen atoms.

A primary object of the present invention is to provide soluble methylol phosphine adducts which contain halogen atoms attached to aromatic carbon atoms which adducts are capable of further reaction with certain nitrogenous agents to produce thermosetting flame-resistant polymers and flame-resistant organic fibrous materials.

We have now discovered that THP reacts with monomeric halogen containing phenolic compounds which contain one or more hydrogen atoms attached to ring carbons at ortho and para positions to the phenolic group to produce soluble halogen containing methylol phosphine adducts. We have also discovered that these adducts can be further reacted with nitrogenous compounds which contain at least two members of the group hydrogen atoms and methylol radicals attached to trivalent nitrogen to produce flame-resistant polymers and flameand wrinkleaesistant textile products.

More specifically, the products and processes of our invention may be described as follows: (1) Soluble halogen containing methylol phosphine adducts are made in solution which have a pH from about 7 to 8 by reacting THP with an essentially monomeric halogenated phenol which has at least one hydrogen attached to a ring carbon, ortho or para to the phenolic hydroxyl group. In order to make the soluble and useful adducts of this invention, there must be an excess of methylol phosphorus radicals (P CH OH) in the adduct. For purposes of the reaction, THP is trifunctional; the functionality of the halogenated phenol is determined by the number of hydrogens attached to aromatic carbons ortho or para to the phenolic OH group. The adducts of this invention are essentially materials which contain the structures of the group consisting of where m and n are integers of l or 2 and the sum of m n is 3. (2) To produce thermosetting polymers in accordance with this invention the halogen containing methylol phosphine adduct is reacted with a nitrogenous compound containing at least two members of the group consisting of hydrogen atoms and methylol radicals attached to trivalent nitrogen atoms. The reaction is carried out by dissolving the halogen containing methylol phosphine adduct and the nitrogenous compound in a suitable medium and then heating as needed until a viscous solution and finally a solid polymer is produced. Polymers produced by this process are insoluble, thermosetting, and flame resistant. The polymers contain a reoccurring trimethylene phosphorus radical P(CH which can be oxidized to a trimethylene phosphine oxide structure ()P(CH (3) To produce flame resistant organic textiles by a heat cure process the textile structure is wetted with a solution containing the methylol phosphorus adduct and a nitrogenous compound containing at least two members of the group consisting of hydrogen atoms and methylol radicals attached to trivalent nitrogen atoms, then drying and heating the textile at a temperature ranging from about to C. for a period of time necessary to promote copolymerization of the methylol phosphine adduct and the nitrogenous agent within or on the textile structure. (4) To produce flame resistant organic textiles by an ammonia cure process, the textile structure is wetted with a solution containing the methylol phosphine adduct then the textile is dried and finally the dried textile is exposed to ammonia or amine gas. The amount of ammonia or amine applied to the dried textile is sufficient to react with substantially all of the P methylol radicals. One ammonia atom is capable of reacting with three P methylol radicals. The resulting product is insoluble in essentially all solvents and the flame resistant product formed in the textile is resistant to laundering and drycleaning.

Halophenolic compounds suitable for use in making soluble adducts of this invention include ortho halophenol, meta halophenol, para halophenol, ortho halo-v phenetole, halophenylphenol, and haloresorcinols. The primary requirement for the halophenol is that it contain at least one hydrogen attached to a ring carbon atom which is ortho or para to a phenolic hydroxyl group. The proper molar ratios of the THP and the halophenolic compound to be used in making soluble adducts is such that the number of methylol phosphorus radicals is greater than the number of hydrogens attached to ring carbons ortho or para to phenolic hydroxyl groups. Preferably one phenolic molecule will be reacted with one THP molecule.

Solvents suitable for use in preparing the methylol phosphine adducts of this invention include dimethylformamide, alcohols such as methanol, ethanol, and isophopanol, and water and mixtures of these compounds. The amount of solvent can be varied as desired. The adducts are used in solution, therefore, it is not necessary to isolate them. Catalysts are not necessary for conducting this reaction. However, it is particularly desirable to maintain pH of the system from about 7 to about 8.

Suitable nitrogenous compounds for use with the halogen containing methylol phosphine adducts in the production of thermosetting polymers include virtually any soluble nitrogenous compound containing at least two members of the group consisting of hydrogen atoms and methylol radicals attached to trivalent nitrogen atoms. Examples of suitable amides include urea, thiourea, melamine, cyanamide, ethyleneurea, propyleneurea, dicyandiamide, hydroxyethylcarbamate, octadecamide, acrylamide, amino acids, methylol and alkylated methylol derivatives of these amides. Examples of suitable amines include ethylamine, methylamine, ethylenediamine, ammonia, analine, and cetylamine. Mixtures of these amides and amines can suitably be employed. Thermosetting polymers are principally prepared by agitating a mixture of the adduct and the nitrogen compound or compounds in a solvent system while heating until copolymerization occurs. The preferred relative amounts of methylol phosphine adduct and nitrogen compounds used to copolymerize can be calculated by conventional methods for condensation polymerization reactions assuming that the functionality of the adduct equals the number of methylol phosphorus radicals on the adduct and that the functionality of the nitrogenous agent is equal to the sum of the number of hydrogens and methylol radicals attached to trivalent nitrogen. Useful products may contain as little as about one mole of the soluble adduct per ten moles of nitrogenous compounds. The use of small quantities of the adduct with large quantities of the nitrogenous compound is made practical when the nitrogenous compound contains N-methylol radicals (N-CH OH) which permit the compounds to form condensation polymers even in the absence of the soluble methylol phosphine adduct. The maximum proportions of the soluble adduct that may be used with a nitrogenous compound for the production of useful polymers is about one mole of the adduct per mole of the nitrogenous compound.

In the production of flame-resistant organic fibrous materials by a heat cure process, the fibrous structure is wetted with a solution containing the soluble adduct and the nitrogenous agent; it is then passed through squeeze rolls to remove excess liquid. The structure is then dried and heated from about 110 to about 160 C. The pH of this treating solution may range from about 3 up to about 7.5. It is generally desirable for the treating solution to contain an acid producing catalyst such as zinc nitrate, magnesium chloride, hydrochloric acid, ammonium chloride, or a mixture of magnesium chloride and an organic acid such as citric acid. The amount of acid catalyst needed may be varied from about 0.5 percent up to about three percent based on the weight of the solution. The concentration of the adduct and the nitrogenous agent in the treating solution can be varied depending upon the amount of flame resistance to be imparted to the organic fibrous structure. Even one or two percent of the adduct and nitrogenous agent produces marked changes in the burning characteristics of the treated textile structure. Where complete flame resistance is to be contributed, about 10 to 20 weight percent must be applied to the textile structure.

In the treatment of organic fibrous structures by the ammonia cure, process, the textile structure is wetted with a solution of the halogen containing soluble methylol phosphine adduct, then the fabric is dried at a temperature ranging between about C. and C. Finally, the fabric structure is exposed to ammonia gas for a few seconds, generally from 2 to 15 seconds. The time of the exposure to ammonia is not so important as the amount of ammonia applied to the fabric. The amount of ammonia applied should be adequate to react with essentially all of the P methylol radicals. If desired, one can complete the insolubilization of the adduct by first exposing the dry fabric to NH gas for about 2 to 10 seconds then passing the fabric through a dilute solution of ammonium hydroxide. However, this order of treatment cannot be reversed. while ammonia is the most convenient nitrogenous gaseous product for use in this chemical cure, other amines may also be used, particularly methylamine and ethylamine. A preferred procedure for treating the textile structure with the amine is to force ammonia gas or methylamine through the textile structure. In this manner, reaction can be completed within one to three seconds.

Virtually any fibrous organic product capable of being impregnated with the soluble adduct can be made flame resistant by use of this invention. Textiles suitable for use in this invention are woven, knit, or nonwoven structures. For best results, the textile structure should contain at least about 25% of a cellulosic fiber. Cellulosic fibers suitable for use in this invention include, cotton, rayon, ramie, flax,-and the like fibers. Various noncellulosic natural fibers can also be used in this invention, such as wool and mohair. Noncellulosic synthetic fibers suitable for use in this invention along with a cellulosic fiber are polyesters, nylons, acrylics, polyvinylchloride. and the like fibers. When cellulosic fibers are blended with flammable noncellulosic fibers it is preferable to have about 50% or more cellulosic fiber in the blend structure. There is thus obtained a flameand glow-resistant textile containing cellulosic fiber treated with an insoluble polymer having halogen, nitrogen and phosphorus in reoccurring trimethylene phosphine radicals,

wherein m and n are integers of 1 or 2 and the sum of m+ n is 3, and x is a halogen.

The following example is illustrative of the invention:

EXAMPLE 1 Soluble methylol phosphine adducts containing phosphorus and halogen were prepared by reacting THP (melting point about 58 C.) with a halogenated phenol as exemplified in Table I. These stable adducts were put into solution with an amine or amide to produce copolymer solutions as shown in Table ll. One of the adducts was put in fabric by a padding process, then the fabric was dried and exposed to NH;, gas for a few seconds to insolubilize the adduct in or on the fabric as shown in Table III. Aliquots of the copolymer solutions 5 from Table ll were also applied to fabric by the padding technique. These fabrics were either heated at elevated temperatures or exposed to NH;, gas to form insoluble flame retardants in or on the cotton as described in Table Ill. Parts of each fabric from Table III were laundered then examined. All samples exhibited a significant degree of flame resistance. The eopolymer solutions of Table ll were polymerized as described in Table W to produce insoluble thermosetting flame resistant products.

TABLE I PREPARATION OF SOLUBLE METHYLOL PHOSPHlNE ADDUCTS CONTAINING HALOGEN AND PHOSPHORUS Adduct Solution Conditions for Designation Reagents in Solution the Reaction I 77-1 4l.3 g (.33 mole) THP Heated at 80 C. for 58 g (.33 mole) p-Bromophenol min. then cooled. I g lsopropyl alcohol (about 40% solids in solution) 77-2 41.3 g (.33 mole) THP Heated at C. for 29 g (I mole) p-Bromophenol 30 min. then cooled. ll0 g lsopropyl alcohol (about 39% solids in solution) TABLE II PREPARATION OF COPOLYMER SOLUTIONS FROM SOLUBLE ADDUCT AND AMIDES 0R AMINES Copolymer Solution Amide or Amine Designation Adduct Solution Used Added to Adduct 77-3 V4 of adduct 77-l 2.7 g cthylenediamine (.082 mole) which contains: and 6.3 g isopropyl alcohol .08 mole THP .08 mole p-Bromophenol 37 g lsopropyl alcohol 774 V: of adduct 77-1 7.5 g of 50% aqueous cyanamide which contains: (0.] mole) .08 mole THP .08 mole p-Bromophenol 37 g lsopropyl alcohol 77-5 V4 of adduct 77-2 5.4 g urea in 7 ml H 0 (.09 mole) which contains: .08 mole THP .04 mole p-Bromophenol 28 g lsopropyl alcohol 77-6 V: of adduct 77-2 56.6 g of 30% aqueous methylolwhich contains:

.08 mole THP .04 mole p-Bromophenol 28 g lsopropyl alcohol urea (.l mole) (The methylolurea contained on the average l.5 methylol groups per urea molecule.)

TABLE III Adduct or Conditions Approximate Copolymer for Depositing Add-On of Properties of Treated Fabric Solution Insoluble Retardant Match After- Fabric Treated Applied to Polymer in After Washing Test glow Fabric Fabric the Treated Hand Strength Color Angle sec.

Textile 50/50 Polyester/Cotton Blend 774 NH gas n 17.1 Good White 2 Good for 6 min.

TABLE III PREPARATION OF FLAME RESISTANT TEXTILES THROUGH USE OF SOLUBLE HALOGEN CONTAINING METHYLOL PHOSPHINE ADDUCTS Approximate Adduct or Conditions Copolymer for Depositing Add-On of Properties of Treated Fabric Solution Insoluble Retardant Match After- Fabric Treated Applied to Polymer in After Washing Test glow Fabric Fabric the Treated Hand Strength Color Angle sec.

Textile Cotton Sheeting 77-5 Heat, 150 9.4 Good White 90 2 Good 3 min.

Cotton Sheeting 776 Heat, 150 l2.5 Good White 110 2 Good 3 min.

Cotton Sheeting 77-2 NH gas Good White lOO 2 Good for l min.

TABLE IV PREPARATION OF INSOLUBLE THERMOSETTING FLAME AND GLOW RESISTANT POLYMERS THROUGH USE OF SOLUBLE ADDUCTS AND AMINES OR AMIDES acid-producing catalyst, an amine or amide nitrog-' enous compound having at least two members of the group consisting of hydrogen atoms and methylol radicals attached to trivalent nitrogen atoms, and an adduet made by reacting tris(hydroxymethyl)phosphine with an essentially mmonomeric,

Copolymer Temperature Time Required Solution Reaction to Produce Nature of Polymer Used C. Insoluble Product 77-3 25 20 min. White, insoluble in H O,

acid and alkali. Formed within 20 min. at l C. Flame resistant and forms black char.

77-4 I00 min. Yellow. hard, insoluble in H O. acid and alkali. Formed by heating on steam cone 20 min. Flame resistant and forms black char.

77-5 I50 l0 min. Yellowv insoluble in H O.

hard. Flame resistant and forms black char.

77-6 150 I0 min. White, insoluble in H O.

Flame resistant and forms black char.

We claim: b. heating the impregnated textile for from about 90 1. A process for producing flame-resistant textiles, to 7 C unti the adduct and nitrogenous comsaid process comprising: pound have reacted to produce an insoluble proda. impregnating a textile with a solution containing an 2. The process of claim 1 wherein the textile structure contains about 25% or more cellulosic fiber.

3. A flameand glow-resistant textile containing cellulosic fiber treated with an insoluble polymer having halogen, nitrogen and phosphorus in reoccurring thimat l lslhasabjae"radicals;H.

halogen-containing phenolic compound having'at wherein m and n are integers of l to 2 and the sum of m n is 3, and x is a halogen. 

1. A PROCESS FOR PRODUCING FLAME-RESISTANT TEXTILE, SAID PROCESS COMPRISING: A. IMPREGNATING A TEXTILE WITH A SOLUTION CONTAINING AN ACIDPRODUCING CATALYST, AN AMINE OR AMIDE NITROGENOUS COMPOUND HAVING AT LEAST TWO MEMBERS OF THE GROUP CONSISTING OF HYDROGEN ATOMS AND METHYLOL RADICALS ATTACHED TO TRIVALENT NITROGEN ATOMS, AND AN ADDUCT MADE BY REACTING TRIS(HYDROXYMETHYL)PHOSHINE WITH AN ESSENTIALLY MMONOMERIC, HALOGEN-CONTAINING PHENOLIC COMPOUND HAVING AT LEAST ONE HYDROGEN ATOM ATTACHED TO A RING CARBON ATOM AT A POSITION ORTHO OR PARA TO THE PHENOLIC HYDROXYL GROUP BY HEATING AND AGITATING SOLUTION CONTAINING AT LEAST AN EQUIMOLAR TO A MOLAR EXCESS OF SAID TRIS(HYDROXYMETHYL)PHOSPHINE RELATIVE TO SAID PHENOLIC COMPOUND SO THAT THE NUMBER OF METHYLOL PHOSPHORUS RADICALS IS GREATER THAN THE NUMBER OF HYDROGEN ATOM ATTACHED TO RING CARBON ATOMS ORTHO OR PARA TO THE PHENOLIC HYDROXYL GROUP THEREBY PROVIDING AN EXCESS OF METHYLOL PHOSHORUS RADICALS (PCH2OH) IN THE RESULTING ADDUCT, AND B. HEATING THE IMPREGNATED TEXTILE FOR FROM ABOUT 90* TO 170*C UNTIL THE ADDUCT AND NITROGENOUS COMPOUND HAVE REACTED TO PRODUCE AN INSOLUBLE PRODUCT.
 2. The process of claim 1 wherein the textile structure contains about 25% or more cellulosic fiber.
 3. A flame- and glow-resistant textile containing cellulosic fiber treated with an insoluble polymer having halogen, nitrogen and phosphorus in reoccurring thimethylene phosphine radicals 